• Open Access

Risk factors for chronic disease in young, midlife and older adults: the PATH Through Life study

Authors


Correspondence to: Lara J. Morris, Building 63 Eggleston Road, Centre for Research on Ageing, Health and Wellbeing, Australian National University, ACT 2600; e-mail: Lara.morris@anu.edu.au

The National Preventative Health Taskforce (2010) has stressed the importance of building and strengthening an evidence base for surveillance of chronic disease risk factors. This study provides recent prevalence statistics of key health determinants and their rates of co-occurrence in a large Australian cohort study. Data were analysed from the most recent collection of the PATH Through Life project (wave 3, 2007–10, n=5,633). Health risk factors were measured by self-report survey items with the exception of hypertension which was measured manually at rest and averaged over two measurements (>140/90 mmHg). Long-term harmful alcohol use was based on the National Health and Medical Research Council 2009 guidelines of more than 14 standard drinks per week. Further details of methods, survey design, procedure, sampling frame, attrition, comparisons to census data and descriptive statistics are provided elsewhere.1

Table 1 presents the prevalence rates of risk factors, and rate of co-occurrence. Consistent with the National Health Survey results,2 we found the most common risk factor was excess weight, followed by hypertension and low levels of physical activity.

Table 1.  Prevalence of individual risk factors and the number of co-occurring risk factors.
%Total Sample20s40s60s
TotalMalesFemalesTotalMalesFemalesTotalMalesFemales
Individual risk factors
 Smoking
 Cholesterol
 Sedentary
 Hypertension
 Alcohol
 Weight

13.31
18.41
36.95
43.57
13.05
59.56

21.11
25.92
25.92
13.18
11.60
49.41

23.71
1.68
17.13
22.40
17.37
58.39

18.81
0.53
33.69
4.99
6.48
41.45

13.73
11.91
39.48
38.98
20.79
65.75

14.11
15.60
30.79
45.76
20.79
72.77

13.39
8.55
47.38
14.38
8.55
59.37

5.31
42.17
44.82
77.78
21.25
62.60

4.90
44.26
37.58
79.23
21.25
65.14

5.75
39.91
52.65
76.21
3.95
59.86
No. co-occurring risk factors
 0
 1
 2
 3
 4
 5
 6

16.06
28.39
27.83
18.88
7.38
1.35
0.11

27.98
38.92
22.57
8.41
1.78
0.34
0.00

28.09
38.97
21.91
8.38
2.06
0.59
0.00

27.88
38.87
23.15
8.44
1.53
0.13
0.00

14.28
28.15
32.10
18.40
5.86
1.10
0.12

13.49
29.04
33.05
17.13
5.83
1.22
0.24

15.00
27.33
31.22
19.56
5.89
1.00
0.00

5.98
17.86
28.06
30.24
14.98
2.67
0.21

7.05
18.16
27.37
31.03
13.55
2.71
0.14

4.82
17.54
28.80
29.39
16.52
2.63
0.29
Total N 5,626 1,775 834 941 2,006 955 1,051 1,845 958 887

Only 16% of all persons sampled were found to have a healthy status characterised by non-use of tobacco, safe use of alcohol, sufficient exercise, healthy weight, no known high cholesterol and normal blood pressure. Most people had at least one risk factor for chronic disease; and more than one-quarter of the adults surveyed reported three or more health risk factors. Previous studies examining cardiovascular disease incidence and all-cause mortality have shown that disease risk and mortality increases substantially in the presence of more risk factors.3

The rates of high blood pressure in the PATH sample are of concern, as high blood pressure has been reported as the largest single modifiable risk factor responsible for cardiovascular mortality. Hypertension represents nearly 8% of the burden of disease and injury in Australia, second only to tobacco use.4 The top five most-common risk factor combinations (Table 2) also highlight its prevalence and co-morbidity of hypertension. More than 40% of the 60s age cohort had a risk factor profile that combined both excess weight and hypertension, or also included high cholesterol and/or sedentary activity.

Table 2.  Five most common risk factor combinations by age cohort.
Rank20s%40s%60s%
  1. Note. Nil = no risk factors, W = excess weight, S = sedentary, T = tobacco smoking, A = Long-term harmful alcohol use, H = hypertension, C = high cholesterol.

1Nil27.98W14.11W,H10.95
2W21.00Nil14.98W,S,H10.68
3S9.40W,H11.22W,H,C10.24
4W,S7.10W,S9.77W,S,H,C10.18
5T,W4.90W,S,H7.73H8.46
Total N   1,775   2,006   1,845

Potential limitations relating to the design of this study include possible participant selection, attrition, and self-desirability bias. It has been documented that people tend to underestimate or under-report their weight and alcohol consumption; and over-report physical activity. Taken together, it is likely that the prevalence rates reported in this study are conservative.

Strengths of this study include the large sample size, objective hypertension measures and broad age range. The results derived from this research provide a detailed picture of the prevalence and high rate of co-occurrence of modifiable health risk factors in the Australian adult population. This suggests that many people presenting to primary care settings have multiple lifestyle-based risk factors. Identifying those with multiple risk factors will enable targeting of multi-domain interventions. The implications of this research are that health promotion, policy and intervention efforts must not only consider health risk factors in isolation, but also consider how an individual risk factor profile may interact with and affect other health risks.

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